1. Field of the Invention
The present invention relates to a tufted pile surface structure and to a method for producing the same in which binder material is concentrated beneath the backstitch portions of the pile yarns.
2. Description of the Prior Art
In the manufacture of a tufted pile surface structure each of a plurality of pile yarns is drawn by a tufting needle through a backing to form face fiber elements and backstitch elements. The face fiber elements lie adjacent to the upper face of the backing while the backstitch elements are disposed along the lower face of the backing. Presently, the backstitch elements are secured by a thermoset or thermoplastic binder placed on the lower face of the backing. In actuality, only a small portion of the binder material serves to hold the backstitch elements in place, while a large portion of the binder material is wasted. Using very large quantities of binder to achieve deeper penetration of the binder through the backing to improve pull-out or unraveling resistance increases binder wastage, stiffens the carpet, and increases carpet weight.
Accordingly, it is believed advantageous to provide a method of manufacture of a tufted pile surface structure that concentrates binder material beneath the backstitch elements to produce a lighter and more flexible carpet structure. Such a structure will also allow the direct deployment xe2x80x9chook-loopxe2x80x9d attachment members on the back of the carpet.
The present invention is directed to a pile surface structure and a process for manufacturing the same Each of a plurality of pile yarns is tufted by a separate tufting needle through a plurality of needle insertion points in the backing to form face fiber elements that lie adjacent to the upper face of the backing and backstitch elements that overlay the lower face of the backing. The insertion points produced by the tufting needles form a pattern of parallel lines that extend longitudinally and transversely along the back face of the backing.
An activated binder material is disposed beneath the backstitch elements to hold the backstitch elements to the backing. The activated binder material is concentrated along the longitudinal and/or the transverse lines of insertion points, with the lower face of the backing member between the adjacent lines of insertion points being left substantially free of binder.
In accordance with this invention the binder material is applied before tufting. The binder material may take the form of either a sheet or a plurality of longitudinally laid strands of binder material that when activated, form stripes of binder extending along the lower face of the backing member. During tufting each needle passes through the binder material so that binder is disposed between the backstitch elements and the lower face of the backing.